Control system for elevators



Dec. 22, 1925- 1,566,385

E. DUNN CONTROL SYSTEM FOR ELEVATORS Filed Dec. 15, 1922 2 Sheets-Sheet l I awuentoz $513 @Homu; 176W Dec. 22 1925.

E. L. DUNN CONTROL s swnm FOR ELEVATORS Filed Dec; 15. 1922 2 Sheets-Sheet 2 Qubwntoz 3513 4; Gum, W

Patented Dec. 22, 1925.

UNITED STATES PATENT OFFICE.

EDWARD L. DUNN, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T0 OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

CONTROL SYSTEM FOR ELEVATORS.

Application filed December 15, 1922.

To all whom it may concern:

Be it known that I, EDWARD L. DUNN, a citizen of the United States, residing in East Orange, in the county of Essex and State of New Jersey, have invented a new and useful Improvement in Control Systems for Elevators, of which the following is a specification.

My invention relates broadly to an apparatus comprising a combination of several mechanisms designed to operate with each other and between which there shall be no relative change of position permitted. More particularly my invention relates to load carrying mechanisms such as to the type of elevators, or their like, which are automatically stopped at the floor landings, wherein it is desirable that the load carrying device or car shall always be in proper relation with its stopping controller mechanism which serves to stop the load carrying device or car level or substantially level with the desired stopping point. The invention particularly involves means that are an improvement over existing means for keeping the car and controller in proper relation witheach other for the purpose set forth.

In the elevator commonly known as the traction elevator, there is occasional slipping or creeping of the cables in relation to the hoisting or driving sheave. When the car in this elevator is controlled automatically to stop by a controller or apparatus driven from the hoisting machine, any slipping or creeping of the cables obviously results in'a change or displacement of the. controller with the car position in the hatchway, with a result that the accuracy of bringing the car to a landing is impaired. An object of the present invention is to provide an improved means for driving the controller that controls the car to stop it, the relation of which controller after once properly adjusted to the car position in the hatchway will not change for level or nearly so stops of the car with its stopping points, though slipping or creeping of the car hoisting cables may occur during the operation of the elevator.

Another object of the present invention is to use the improved means embodied in the invention as the load carrying or car hoisting cable. I

In the accompanying drawings, Figure 1 illustrates diagrammatically the invention embodied in a traction elevator system.

Figure 2 illustrates more or, less diagram- Serial No. 607,244.

matically a controller or apparatus for the car iii Figure 1, which is not seen'in the Figure Figures 3, 4 and 5 illustrate diagrammatically other embodiments of the invention in a traction elevator system.

Figure 6 illustrates diagrammatically another embodiment of the invention.

Figures 7, 8 and 9 illustrate in different views a sheave or pulley of a construction such as usedin the embodiment of the invention.

Figure 10 illustrates more or less diagrammatically a belt or tape hitch, the latter its true name in this invention and shown fixed to the top of an elevator car in this figure.

Like reference characters denote similar parts in all of the figures.

Referring now to Figure 1, it comprises an elevator car A, and a car counterweight B, connected to the ends of a hoisting cable 1, which runs over a driving or hoisting sheave C. At both the top and bottom of the car A, there is located a tape hitch 2, as of Figure 10, and to each tape hitch 2, there is secured one end of one of two separate fiat belts or tapes, 3 and 4, which are made preferably of steel. The tape 3 runs over a sheave 5 as of Figure 7 and is wound thereon a number of times equal to the travel of the car and some additional, and fastened to the sheave at its other end. Sheave 5 constitutes a reel. The tape 4'is directed from the car and after passing under a sheave 6 of a weighted tension device D at the bottom or the elevator well, is brought up to and over the sheave 5, and wound thereon a number of times equal to the travel of the car and some additional, and also fastened at its other end thereto like the tape 3, and as shown in Figure 9. The sheave 5 necessarily has two grooves therein, a groove for each of the tapes 3 and 4, whereas the sheave 6 needs only one groove and for the tape 4. The sheave 5 is as shown in the Figures 7, 8 and 9 through which and in its center full part there is positioned a pin 7 to which is fastened an end of each of the tapes 3 and 4. The tapes are fastened to the pin 7, by a loop formed at an end of each, which loop is obtained by riveting the end turned over the tape. In the bottom of each groove of from their fixed point in the sheave to its respective groove in the sheave and therein the tape is Wound in layers one above the other and then passed out of the groove, the other end of each of the tapes, in this instance, being fastened to the car C as in Figure 1. The top opening of the slots 8 in the sheave are not directly over their bottom opening but instead are to one side of their top opening, and obtained by cutting the slots on a curved line. In the Figure 9 the curve of the side to the observers right, of the slot shown in full lines is more or less carried out; this is done to relieve the tape from too sharp a bend at this point whereas the tape might become weak at this point if too sharp a bend were made and break. In Figure 10 therein is shown the form of hitch 2 used to anchor the other ends of the tapes 3 and l. The hitch comprises a block or disc fastened to a support 10, the support, in this instance, being fastened to the top of the car C. The tape is fastened to the block at its surface 11 and then passed or wound around the block several times, twice for illustration. This manner of hitch holds the tape without weakening it, and at the same time affords a convenient means to adjust the length of the tape when installing it in practice. "Still referring to Figure 1, the tape 3, if the car is moving up, winds on the sheave 5, and tape 4 at this time winds ofi the sheave. The tension device D on the tape 4, keeps that tape taut; it also effects keeping the tape 3 taut, and also compensates for the changing diameters of both tapes on the sheave 5, as the car is operated. As the sheave 5 is driven in exact time or synchronously with the car, the sheave in rotating represents exact travel of the car. If the shaft 12 that the sheave is on is adapted to drive a mechanism or a floor controller, diagrammatically represented by Figure 2, adapted to automatically stop the car at its stopping points, the car will be stopped level or nearly so with its stOpping points, and if slipping or creeping of the car hoisting cables should ocur in the operation of the elevator, which will change fixed points on the hoisting cables with relation to the sheave, the car will still be brought to a level or nearly so stop with the stopping point. Naming a floor controller is thought to be sufficient to carry out the intentions of stopping the car automatically at the car stopping points without disclosing a system of circuits, as a floor controller is a well known piece of apparatus to those skilled in the load carrying hoisting machine art.

'For the purpose of ascertaining the reliability and accuracy of the present invention to stop a car level or nearly so with its stopping points, a test was made: The elevator car used had a run to a height of 90 feet at a speed of 400 feet per minute, the car traveling about 11 miles per day; at the time of this writing the car has travelled 2052 miles. The double grooved sheave 5 used was 12 inches in diameter measured from the bottom of its grooves, and revolved 28% times during a full trip of the car. The tapes are of tempered steel, 0.01 inch thick and 0.75 inch wide. Two measurements of the tapes are taken daily: there is a difference in the stop of the car at its bottom stopping point, but only ranged from of an inch to of an inch, the same measured difference is also found in the car stops at its top stopping point. The differenre cited was perhaps due to inaccurate measurements rather than due to a change in the condition of the tapes. It is presumed that the car hoisting cables slipped or crept on the driving sheave during the test, that the difference noted of the car stops was not due to this, as the sheave or wheel 5 is positively geared to the car and is not aifected by the cars changed position with its hoisting machine because of the hoisting cables slipping or creeping on the driving sheave as pointed out herein but that the difference was due rather to inaccurate measurements as first thought of and stated above.

Figure 3 shows the sheave 5 carried by the car, the tape 3, of which one of its ends is attached at the top of the well room, and its other end in the sheave 5 as before, the tape 4 also having one of its ends fastened in the sheave 5 as before stated and its other end to a tension weight D at the bottom of the well room that keeps both tapes 3 and 4: taut. This arrangement may be used where the controller E is carried by the car.

Figure 4 shows the sheave 5 and the controller E for stopping the car at the top of the well room while the tension weight D for keeping the tapes taut travels with the elevator counterweight B. The single grooved sheave 6 is dispensed with in this figure as in Figure 3, accordingly there is less bending in the tape at, of Figures 3 and 4, as it makes only a single bend around the sheave 5.

Figure 5 shows the arrangement in Figure 3 reversed, that is, the sheave 5 and controller E in the figure are at the bottom of the elevator well, the sheave 6 is positioned on the elevator counterweight over which the tape 4 is hung and weighted down by a tension weight D to keep the tapes taut.

Figure 6 shows the sheave 5 as the hoisting or driving sheave for the car A in the figure, as well as used for driving the floor controller E, and the tapes 3 and 4 as the load carrying or car A hoisting cables. The two grooved sheave 5 and the tapes 3 and 4 used as hoisting sheave and load carrying cables respectively will make a direct and positive drive for the car A, having at the same time the advantage of a traction drive.

Havingthus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. An elevator mechanism comprising in combination with the car, a reversible reel, a pair olf tapes secured to said reel and adapted to spirally wind and unwind in opposite directions thereon, and means for enabling the movement of the car to rotate said reel and respectively wind and unwind the two tapes.

An elevator mechanism comprising in combination with the car, a reversible reel, a pair of tapes secured to said reel and adapted to spirally wind and unwind in ()PPtJbltC directions thereon, and means for enabling the movement of the car to draw oli one tape from said reel and thereby simultaneously cause the reel to wind up the other tape.

25. In an elevator system, the combination with the car, and a control mechanism having a reversible reel; of a tape wound on said reel and adapted to be unwound as the car moves in one direction to correspondingly rotate said reel, and a second tape wound on said reel in the opposite direction to the first mentioned tape and adapted to exert a pull on said reel in a direction to rewind the first tape when the car moves in the other direction.

4. in an elevator system, the combination with an elevator car and a controlling mechanism comprising a reversible reel, of means for driving said reversible reel in unison with the movement of the elevator car, said means comprising a pair of tapes secured to said reel and adapted to spirally wind and unwind side by side in opposite directions thereon, and means for enabling the movement of the car to draw oif one tape from said reel and thereby cause the reel to simultaneously wind up the other tape.

5. In an elevator system, the combination with an elevator car and a controllin mechanism comprising a reversible reel; 0 means for driving said reel in unison with the movement'of the car, said means-comprising a pair of tapes secured to said reel and adapted to spirally wind and unwind side by side in opposite directions thereon. and means for enabling the movement of the car to rotate said reel and respectively wind and unwind the two tapes thereon.

(5. An elevator mechanism comprising in combination with the elevator car, a reversible reel, a pair of tapes adapted to spirally wind and unwind side by side in opposite directions on said reel, an anchorage for the first of said tapes for enabling the movement oi the car in one direction to rotate said reel and unwind said first tape while winding the second tape and means operatively connected with said second tape for rotating said reel in the opposite direction and ire-winding the first tape during movement of the car in the other direction.

7. An elevator mechanism comprising in combination with the elevator car, a reversible reel, a pair of tapes adapted to spirally wind and unwind side by side in opposite directions on said reel. an anchorage for the first of said tapes for enabhng the movedirections on said reel, an anchorage for the firstof said tapes for enabling the movement of the car in one direction to rotate said reel and unwind said first tape while winding the second tape, and means operatively connected with said second tape for rotating said reel in the opposite direction and rewinding the first tape during movement of the car in the other direction, said means including a device for yieldingly maintaining at all times a tension in said second tape.

9. An elevator mechanism comprising in combination with the elevator car, a reversible reel, a pair of tapes adapted to spirally wind and unwind side by side in opposite directions on said reel, an anchorage for the first of said tapes for enabling the movement of the car in one direction to rotate said reel and unwind said first tape while winding the second tape, and means operatively connected with said second tape for rotating said reel in the opposite direction and rewinding the first tape during movement of the car in the other direction, said means including a device for maintaining at all times a tension in'said second tape and for compensating for change of diameter of the outer convolutions of the tapes on the reel as they wind and unwind.

In testimony whereof, I have signed my name to this specification.

EDWARD L. DUNN. 

